Thirteen new jatrophane diterpenoids, euphoresulanes A-M (1-13), and seven known analogues (14-20) were isolated from the whole plants of Euphorbia esula. Their structures were elucidated by extensive spectroscopic analysis, and the absolute configurations of 1, 6, and 10 were confirmed by single crystal X-ray diffraction. Compounds 1-20 were screened for the multidrug resistance (MDR) reversal activity on P-glycoprotein (Pgp)-dependent cancer cell line HepG2/ADR, and 1, 2, 4, 6, and 8 exhibited comparable activity to the positive drugs. Euphoresulane H (8), the most active MDR modulator, could enhance the efficacy of anticancer drug adriamycin to ca. 33 folds at 5 μM. The structure-activity relationship (SAR) study revealed that the acyloxy substitution at C-9 is essential to the activity and presence of H-2 was favorable.

中文翻译：

---

Euphoresulanes AM，来自大戟（Euphorbia esula）的结构多样的麻风树二萜类化合物。

从大戟大戟的整个植物中分离出十三种新的麻风菊二萜类化合物，大戟类（AM）（1-13）和七个已知类似物（14-20）。通过广泛的光谱分析阐明了它们的结构，并且通过单晶X射线衍射确认了1、6和10的绝对构型。筛选化合物1-20对P-糖蛋白（Pgp）依赖性癌细胞系HepG2 / ADR的多药耐药性（MDR）逆转活性，并且1、2、4、6和8的活性与阳性药物相当。最具活性的MDR调节剂Euphoresulane H（8）可以增强抗癌药阿霉素对ca的疗效。在5μM下33倍。结构-活性关系（SAR）研究表明，C-9处的酰氧基取代对于活性至关重要，H-2的存在是有利的。